This: http://forum.mikrotik.com/t/wan-load-balancing-between-2-isps-one-with-cgnat-and-another-in-bridge-mode-real-ipv4-address/150195/2
and this: http://forum.mikrotik.com/t/wan-load-balancing-between-2-isps-one-with-cgnat-and-another-in-bridge-mode-real-ipv4-address/150195/2